2014-2015 60% FTE Post-doctoral Research Assistant, University College London, Department of Geography, UK. Working on NERC-BESS research grant Lake BESS, PI Dr Carl Sayer. I have led the planning and execution of the entire project including budget management, field work, data collating, analysis and write up. I report our progress on our blog “Lake BESS”.

2013-2015 60% FTE Stay-at-home Dad. I had to take multi-tasking, prioritisation, time management and learning new skills to a whole new level in order to write up my thesis and conduct my post-doctoral research while looking after our daughter 3-5 days a week from her birth in January 2013 to January 2016.

Research

For the Lake BESS project, we are looking into how biodiversity regulates ecological balance within lakes and would like to assess the consequences of biodiversity loss for the provision of ecosystem services.

Ecosystem services from lakes are extremely diverse: recreation, tourism, water purification, flood prevention, provision of fish for anglers and fisheries and other supporting services such as carbon storage for climate mitigation.

Because of this variety, changes in lake ecological functioning may affect the different services in different ways, rendering best practices for restoration and management difficult to establish.

One aspect we are particularly interested to develop in LakeBESS is the importance of ecological connectivity between lakes for their biodiversity. Connectivity may be a major factor determining lake ecosystem resilience because it counter-balances the negative effect of local extinction by increasing species re-colonisation.

PhD work:

My PhD thesis addressed the methodological challenges of determining the variability of large herbivore populations through time and their impact on European vegetation. Large herbivores are at the heart of conservation policy, however, opinions widely diverge on whether we should aim for fewer herbivores and managed populations or, on the contrary, as advocated by the rewilding movement, more herbivores and self-regulating populations acting as ecosystem engineers.

This controversy has roots in a debate regarding the nature of ecosystems before the prevalence of human activities. Baseline ecosystems are either described as continuous forest cover with passive large herbivores, or, in contrast, as mosaics with patchy forest cover driven inter alia by bison, aurochs and horses, now rare or extinct in Europe.

The main obstacle in moving this debate forward is a poor understanding of large-herbivore densities in the past. I analysed modern pollen and spore assemblages from known environmental settings to improve palaeoecological interpretation of fossil assemblages dating the pre-human (baseline) period.

The sites investigated are the rewilded grasslands of the Oostvaardersplassen (The Netherlands), the mosaic habitats of The New Forest (UK) and the old-growth closed-canopy forest of Białowieża (Poland).

I demonstrate that the common practice of interpreting pollen percentages fails to estimate past forest cover in situations with natural grazing. As an explanation, I suggest that pollen productivity fluctuates with biotic factors such as herbivory and canopy shading. As a result, new insights into the baseline debate require additional lines of evidence.

Thus I developed an existing methodology to reconstruct past herbivore presence using fossil dung fungal spores. I synthesised our knowledge on this method with an emphasis on spore identification and, finally, I demonstrate that dung fungal spore abundance in lake sediments can be translated into large herbivore numbers.

The evidence presented herein contributes to the debate on re-wilding, thereby addressing the fundamental challenge of nature conservation in the human-dominated landscapes of Europe.

Publications

Baker, A.G., Cornelissen, P., Bhagwat, S.A., Vera, F.W.M. & Willis, KJ. (2016) Quantification of population sizes of large herbivores and their long-term functional role in ecosystems using dung fungal spores. Methods in Ecology and Evolution.